1. Field of the Invention
The present invention relates to a method of replenishing a solution for a photosensitive material processor and a photosensitive material processor capable of stably maintaining the quality of a processing solution.
2. Description of the Related Art
Hitherto, a photosensitive material processor, called a "Mini-Lab", requires replenishment of a processing-solution in a quantity corresponding to the amount of the processed photosensitive material in order to maintain the quality of the processing solution.
When a replenishment solution (a replenishment solvent or a replenishment solute) has been injected into the processing solution, the volume of the processing solution is enlarged and an excessive amount of the processing solution flows over the processing tank. If the processing system is a cascade system, the excess processing solution is cascaded into another processing tank. If the processing tank is structured such that waste water is discharged, the overflow processing solution is discharged into a waste-water tank or a waste-water processing tank.
In a case where the processing solution is replenished in a large quantity and if the photosensitive material is, for each day, processed in a quantity larger than a predetermined quantity, replenishment is performed in a sufficient quantity.
However, the quantity of replenishment has been reduced in recent years such that the amount of replenishment for a unit quantity of each photosensitive material and the amount of the waste water are reduced.
Since the reduction in the amount of replenishment results in the operation for replenishing the solution to the processor and discharging waste water being reduced, the labor for a user and the amount of waste water can be reduced. Therefore, the cost for processing waste water and space for storing waste water can be saved. Since the reduction is a preferred fact for environmental protection, the amount will furthermore be reduced.
However, the reduction in the amount of replenishment encounters a problem in that it is difficult to stably maintain the quality of the processing solution in the processor.
If the amount of replenishment per unit time is too small due to the reduction in the amount of replenishment or if the processed amount of the photosensitive material per day is too small attributable to employment of the small-quantity replenishment method, the processing solution stored in the processing tank of the processor may evaporate and be condensed. If the amount of evaporation is larger than the amount of replenishment, the level of the processing solution in the processing tank is lowered.
The above-mentioned condensation, as has been known, deteriorates the processing performance of the processing solution.
In order to correct the amount of evaporation, some processors developed in recent years are provided with a system for adding water. Although the foregoing method is effective in correcting the amount of evaporation, it is difficult to accurately be correct the amount of evaporation by adding water in a in which uses the processing solution is used in a small quantity or which uses the small replenishment method. The foregoing method encounters a difficulty in stably maintaining the concentration of the stored processing solution because the concentration of the same is considerably affected by condensation or dilution attributable to the inadequate quantity of the added solution in a case where the quantity of a replenisher solution (the quantity of chemicals) is small.
As a method of correcting the amount of the evaporated solution, a method has been suggested in which the amount to be processed corresponding to the environment of the processor is previously measured and water is added in accordance with obtained data (see Japanese Patent Application Laid-Open (JP-A) No. 4-1756 and Japanese Patent Application Laid-Open (JP-A) No. 5-181250). Another method has been suggested in which detection of lowering of the level of the processing solution in the processor occurring due to evaporation from the processing tank is performed and water is added (see Japanese Patent Application Laid-Open (JP-A) No. 7-5657).
In the latter method, in which the level is detected in accordance with a total result of replenishment, carry over by which the processing solution is carried from another tank when replenishment is performed or when the photosensitive material is carried, evaporation and the like, a critical error cannot be prevented. Thus, this method cannot be adapted to the small replenishment method.
Although the former method, in which the correction is performed in accordance with the previous measurement, is able to accurately correct the level of the solution, error sometimes takes place between the actual data and the previous value.
As described above, the amount of evaporation in the processing tank cannot easily and accurately be detected.